1. Field of the Invention
With the advent of the polyisobutenyl succinimides of alkylene polyamines, numerous and varied ashless detergents for internal combustion engines have been prepared. These compositions which comprise a long chain hydrocarbon group and a polar amine end are advantageous in lubricating oils because they do not have metals which produce ash and they are able to stably disperse deposit producing materials in the lubricating oil. Furthermore, the compositions do not in themselves lead to deposits or decompose only slowly to deposit-producing materials.
In fuels, compositions are employed which not only provide detergency in the carburetor, but aid in the removal of deposits from the intake ports and valves. In addition, preferred additives are introduced by blow-by or other mechanisms from the piston chamber into the lubricating oil in the crankcase, so as to further aid detergency and dispersancy in the lubricating oil.
2. Description of the Prior Art
Urea compositions which have found use as detergents in lubricating oils are disclosed in U.S. Pat. Nos. 3,296,128, 3,316,619 and 3,385,791.